Magnesium Oxide Spinel Powder for High-Strength Ceramic Sintering

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Solution Overview

Problem

Existing methods for producing spinel powders result in sintered bodies with low strength and instability, nonuniform composition, and insufficient spalling resistance, despite efforts to improve corrosion and water resistance.

Innovation Solution

A magnesium oxide-containing spinel powder with a specific particle diameter and size distribution, combined with controlled Mg and Al composition, is produced through calcination and grinding, ensuring a uniform spinel phase and enhanced mechanical properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If magnesium oxide-containing spinel powder with controlled particle size distribution and composition is produced through calcination and grinding, then the sintered body achieves high strength and stability, but the production process becomes more complex compared to conventional methods

Engineering Contradiction:
Improvesintered body strengthVSAvoidproduction process complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by controlling the particle size distribution of the spinel powder before sintering. The powder is prepared with a specific D50 range (0.3-10 μm) and composition ratio (MgO 50-90 wt%, Al2O3 10-50 wt%) through calcination and grinding processes, which ensures uniform reactivity and sintering behavior, leading to high-strength sintered bodies with stable mechanical properties.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent employs parameter changes by optimizing the composition ratio of MgO and Al2O3, as well as the particle size distribution parameters (D50, D90-D50)/(D50-D10)). By adjusting these parameters within specific ranges, the sintered body achieves enhanced strength and stability while maintaining production feasibility.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If conventional spinel powder production methods are used, then the production process is simpler, but the resulting sintered bodies exhibit low strength and insufficient strength stability

Engineering Contradiction:
Improveproduction easeVSAvoidsintered body strength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent improves sintered body strength by changing the particle size distribution parameters of the spinel powder. The D50 is controlled at 0.3-10 μm, and the uniformity ratio (D90-D50)/(D50-D10) is maintained at 1.0-5.0, which ensures uniform packing and sintering, resulting in high-strength sintered bodies with consistent mechanical properties.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies local quality by ensuring uniform composition distribution within the spinel powder. The MgO content is controlled at 50-90 wt% and Al2O3 at 10-50 wt% throughout the powder, which guarantees homogeneous sintering and consistent local properties in the sintered body, leading to improved overall strength and stability.

Inventive Principle:
Principle #3Local quality

3Strength

If electromelted spinel is used to achieve high strength, then the sintered body has relatively high strength, but the composition is nonuniform and strength cannot be controlled to be constant

Engineering Contradiction:
Improvesintered body strengthVSAvoidcomposition uniformity
Core Design Contradiction:
StrengthVSStability of the object's composition

Solution Approach 1:

The patent achieves homogeneity by controlling the composition ratio of MgO (50-90 wt%) and Al2O3 (10-50 wt%) to be uniformly distributed throughout the spinel powder. This uniform composition, combined with controlled particle size distribution, ensures homogeneous sintering and constant strength in the resulting sintered bodies, eliminating the nonuniformity problem of electromelted spinel.

Inventive Principle:
Principle #33Homogeneity

4Reliability

If magnesium oxide is used to improve corrosion resistance, then corrosion resistance is excellent, but spalling resistance is poor due to large thermal expansion coefficient and particle cleavage

Engineering Contradiction:
Improvecorrosion resistanceVSAvoidspalling resistance
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent uses composite materials by combining MgO and Al2O3 in a spinel structure with controlled composition ratio (MgO 50-90 wt%, Al2O3 10-50 wt%). This composite spinel structure maintains the excellent corrosion resistance of MgO while the Al2O3 component reduces the thermal expansion coefficient and improves spalling resistance, achieving a balance between the two properties.

Inventive Principle:
Principle #40Composite materials

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The approach yields ceramic sintered bodies with high strength, stability, and controlled thermal expansion, overcoming previous limitations in strength and spalling resistance.

Implementation Method 1

A magnesium oxide-containing spinel powder with a specific particle diameter and size distribution, combined with controlled Mg and Al composition, is produced through calcination and grinding

Methodology Applied
Scientific EffectCalcination: Heat Treatment

Data Source

PatentUS10766783B2Magnesium oxide-containing spinel powder and method for producing same
Publication Date: 2020.09.08 TATEHO CHEM IND CO LTD

AI summary

Provided is a magnesium oxide-containing spinel powder capable of producing a ceramic sintered body having high strength and excellent strength stability. In the magnesium oxide-containing spinel powder, a 50% particle diameter (D50) is 0.30 to 10.00 μm, a ratio (D90-D50)/(D50-D10) of a difference between a 90% particle diameter (D90) and the 50% particle diameter (D50) and a difference between the 50% particle diameter (D50) and a 10% particle diameter (D10) is 1.0 to 5.0, and a composition ratio of Mg and Al in terms of an oxide equivalent content is 50 to 90% by weight of MgO and 10 to 50% by weight of Al2O3.